Automatic-motor-starter.



H. F. KRANTZ.

AUTOMATIC MOTOR STARTER.

APPLICATION FILED FEB. 18. I916.

Patented May 21, 1918.

3 SHEETS-SHEET I.

H. F. KRANTZ. AUTOMATIC MOTOR STARTER.

PLICATI FILED FEB. 18. I916.

Patented May 21,1918.

3 SHEETSSHEET 2.

H. F. KRANTZ.

AUTOMATIC MOTOR STARTER.

APPLICATION FILED FEB. 18. I916;

Patented May 21,1918.

3 SHEETS-SHEET a.

vwawfoz 3 MRM;

Elihu wi UNITED STATES PATENT Ol l lGl-ii.

HUBER/I F. KRANTZ, OF BROOKLYN, NEW YORK, ASSIGNOB, TO KRANTZ MANUFAC- TUBING- COMPANY, INC., OF BROOKLYN, NEW YORK, A CORPORATION OF NEW YORK.

AUTOMATIC MOTOR-STARTER.

Application filed February 18, 1916.

To all whom it may concern:

Be it known that I, HUBERT F. KRAN'rz, a citizen of the United States, and residing at Brooklyn, in the county of Kings and State of New York, have invented a new and Improved Automatic Motor-Starter, of which the following specification is a full disclosure.

This invention proposes a semi-automatic motor starting switch devised to compel the first inrush of current due to the initial low back electro-motive-force of the motor to be drawn directly from the mains independently of the motor fuses and thus avoid the blowing of said fuses during the initial starting period of the motor.

To provide an automatic device governing the lapse of time before the current is ta en through the motor fuses, is one of the primary objects of this invention; and to devise simple and rugged mechanism for doing so is the chief aim of the illustrated embodiment thereof.

Another purpose is to create a semi-automatic means whereby the hand is enabled unrestrictedly to throw the switch into its motor starting position; and in which the subsequent act of connecting the fully started motor with the mains through the fuses will be performed automatically and without requiring any personal attention on the part of the user.

Other objects will be in part obvious from the annexed drawings and in part indicated in connection therewith by the following analysis of this invention.

This invent-ion accordingly consists in the features of construction, combinations of parts, and in the unique relations of the members and in the relative proportioning and disposition thereof; all as more completely outlined herein.

To enable others skilled in the art so fully to comprehend the underlying features thereof that they may embody the same by the numerous modifications in structure and relation contemplated by this invention, drawings depicting a preferred form have been annexed as a part of this disclosure, and in such drawings, like characters of reference denote corresponding parts throughout all the views of which Figure 1 is a plan of the automatic switch mechanism. Fig. 2 shows the switch ele- Speeification of Letters Patent.

Patented May 21, 1918.

Serial No. 79,098.

ments as arranged in their normal running position. Fig. 3 shows more specially the means for automatically producing the operation of the parts.

Referring to the drawings, 1 indicates a base plate of insulating material on which is mounted one or more bus-bars 2-. As several bus-bars and switches are shown which are of identical construction, it will suflice to describe but one. Overlying these bus-bars is a rocking blade holder formed of parallel strips 3 and a having'their ends secured at the one end to a gudgeon providing the pivot 5 which is mounted in a side plate 6 uprising from the base board 1. At the opposite end, the strips 3 and 4: are secured to a part 7 providing arms 8 for actuating the same and providing also a shaft 9 which is journaled in the plate 10. A spring 11 tends constantly to urge the brush-holder, formed of the plates 3 and at, in an anti-clockwise direction, as shown by the drawings. Mounted on the brushholder and insulated there from by means of the plates 12 are a number of brushes 13. preferably of resilient construction, as shown, although a knife-blade arrangement is equally applicable. When the brush-holder is in the position shown by Fig. 2 with the blades contacting with the bus-bars, the posit-ion is normally retained by means of a toggle formed of the links let and 15, the latter being pivoted about the fixed pivot 16 and the former being pivoted to the pin 17 mounted on the arm 8. A floating pivot 18 connects these links and they are prevented from moving out of the dead center position shown by Fig. 2 by an abutment againstthe pin 19.

In this embodiment, the switch just described is that ordinarily employed during the normal running of the motor, but in addition to that switch this invention proposes an auxiliary switch S which is used merely during the initial starting period of the motor when a great inrush of current i consumed owing to the momentary low reactance of the motor.

This auxiliary switch may be mounted and constructed in precisely the same manner as that previously described and therefore these details need not be further elaborated. It is to be noted that the location of the switch S with relation to the switch 13 is of no consequence providing, however, that it derives current independently of the fuse plugs intervening between the switch 13 and the main line.

A very important characteristic of this invention lies, furthermore, in the mechanism whereby the switch S may be used temporarily for starting purposes and the switch 13 for normal running purposes; the functioning being such that when the motor is to be started the switch S will be caused to establish contact with the main line either simultaneously or slightly before the switch 13 and within a few moments thereafter the switch S will be disconnected while leaving the switch 13 in operation.

One very simple instrumentality for achieving this result is shown in the drawings, and it consists of a connection between the device controlling the switch 13 and the device controlling t 1e switch S such that the latter device will be positively operated either immediately before or simultaneously with the other device so as to throw the switch S into its closed circuit position not appreciably later than the switch 13 is caused to assume the same position. This mechanism also embodies means effective during subsequent movement thereof to snap open switch S, and it also embodies means enabled to go into action during a still later movement of the mechanism to snap open the switch 13 to effect the stoppage of the motor. All of this may be accomplished by a very simple arrangement which here merely assumes the form of a lost motion link together with a link actuator.

This lost motion link is indicated by L and it is provided with an opening 21 and engages the pivot 22 of the toggle controlling switch S, whereby this toggle may be either erected or broken by a shifting of the link L. The other end of the link L is an elongated slot 23 which provides lost motion and enables two different contact surfaces to come into action at different times with relation to the floating pivot 22. That is to say, it provides a contact surface at which becomes eh ective on the floating pivot 18 at substantially the same time that the opening 21 becomes effective on the floating pivot 22, when the link L is moved in the direction causing the switch blades to make contact with the bus-bars.

On the other hand, the contact surface bears such a relation to the opening 21 that it will not become effective against the floating pivot 18 until the opening 21 has already broken the other toggle by shifting the floating pivot 22. Upon a continued motion of the lever L, the contact surface 1.3 will become eiiective against the pivot 18 so to break the toggle thereof and open the switch 13. It is to be noted that the opening 21 provides a certain amount of lost motion with respect to the floating pivot 22 so that when the latter ha reached its final position, the link L may still move sufficiently farther to break the toggle of the blade 13; the lost motion of the slot 23 being considerably greater than that of the opening 21 since the latter need only be sufficient to enable the link L to throw the floating pivot 18 across its dead center, whereas the lost motion in the slot 23 must be sufficient to accommodate the full swing of the floating pivot 18.

The terminal leading to the motor i indicated by 25 and is connected independently of a fuse with the terminal or contact 26 with which the switch S establishes con nection; whereas the terminal 25 is connected with the other contact 27 of the switch 13 only through an intermediary in the nature of a fuse P. A convenient manner of doing this consists in providing a block M of insulating material and arranging a U-shaped strip N on one end of it and another U-shaped strip 0 on the other end of it and providing the ends of these strips or conductors with spring-clips 31 and suitably formed to receive the ends of the fuse P.

For the purpose of operating the switch blades by means of the link L, a manually or automatically actuated element may be employed. Reduced to its simplest terms, this element may comprise a lever B pivoted at 32 to the side plate 10 and having a pin 33 entering a lost motion aperture 34 in 100 the link L. This lost motion permits the springs to efiect a quick break of the switch blades without overcoming the inertia of the lever This lever preferably embodies a detent mechanism for holding it in its run- 105 ning position and to that end a small spring-pressed pawl 35 is adapted to enter a suitable recess 36 in the edge of the plate 10 and hold the starting lever in place. A pressure of the hand will, however, suflice 110 to cause the pawl to override this recess.

This invention furthermore proposes an automatic instrumentality for actuating the lever B- when it has been released by the hand. This mechanism is of such a nature 115 that while shifting the switch from the motor starting to the normal running position, sufficient time is consumed to enable the motor to develop its full running speed and thereby create sufhcient back electro-motive-force so that no great inrush of current will be drawn from the mains.

This mechanism is of such a variety that when the hand lever is thrown into the motor starting position, it will set the mechanism so that it may subsequently function topartially throw the hand lever; and preferably the connection will be such that the hand supplies the instrumentality with the power necessary for-this'purpose,

as by lifting a weight or winding a spring.

Of course, this instrumentality may assume various forms, but one of the many embodying my invention and well suited for the purpose, ,is illustrated specifically by Figs. 1 and 3 and is constructed as follows:

An actuator A in the form of a segment of a gear wheel is pivoted to swing about a suitable center, as for instance a stud 32 which also pivots the hand lever B, and this actuator A has an abutment 64 adapted to bear against a contact surface or shoulder 0 provided by the lever B so that when the lever is lifted, it may cause the actuator A to swing anti-clockwise; and likewise, the actuator A may thereupon return the lever B to its intermediate or normal running position. A stop '1) is arranged so that the actuator A will not urge the hand lever B beyond its intermediate or normal. running position and so that the detent 35 may retain it yieldably in that position. WVhen the .handlever R is lifted and the actuator A tageously be in the form of an escapement comprising an escape wheel h and a detent device through which periodical manipulations are imparted to a pendulum E to keep it in oscillation, and through which, in turn, motion is imparted or permitted by the return movement of the pendulum. This escapement may consist of a rock block C from which the pendulum E is suspended by means of the pendulum rod 10. This rock block G carries two arms m and a providing pivots 7c and 0 respectively upon which are swung the weighted or gravity-acting pawls .2 and 0;. These pawls engage the teeth it whenever they are permitted to do so by the pins 3 and to. These pins are contained within openings in the pawls z and as which provide sufficient back-lash so that during the power storing movement of the actuator A, the teeth It, will be enabled freely to swing past these pawls ratchetwise. On the other hand, under the impulse of the teeth h, the pawls z and w are successively pressed to one side and slipped past the teeth, thereby maintaining the pendulum E in a state of oscillation. This results in a steady and deliberate return of the actuator A which is the sort of motion required for returning the switch handle R, to its normal position.

It is to be noted that the above-described automatic instrumentality need not be connected with the hand lever R so as to be moved thereby when the latter is being brought to its off position. Even so, it will not be possible to start the motor by moving the hand lever B directly into and leaving it in its intermediate position, because the mechanism is of such a nature that the hand lever R is inefiective to throw the normal running switch 13 into its closed circuit position appreciably before the temporary starting switch S has also been thrown into its closed position.

This peculiarity is inherent in the nature of the toggle and lost motion operating parts. In other words, when both of the toggles are broken, the hand lever B may be brought to its intermediate position without actuating either switch by reason of the lost motion in that direction. This is an important feature because it safeguards the entire organization from accidental or ignorant manipulation on the part of the user.

As many changes could be made in this construction without departing from the scope of the invention as defined in the following claims, it is intended that all matter contained in the above description or shown in the accompanying drawings, shall be interpreted as illustrative only and not in a limiting sense.

Having thus revealed this invention, I claim as new and desire to secure the following combinations of elements, or equivalents thereof, by Letters Patent of the United States 1. A switch mechanism combining a first and a second switch blade; means for individually holding said switches in on position simultaneously; automatic time controlled means for rendering ineffective the means for retaining said first switch in on position; and manually operable means for rendering inelfective the means for holding the two second switch on.

2. A switch mechanism combining a first and a second switch; automatic means acting through a pre-determined time interval for drawing said first switch; and manually operable means for throwing said second switch.

3. A mechanism of the nature disclosed combining a hand lever adapted to be moved through a pre-determined are two switches connected to be moved into on position by full movement of said lever; a member movable by said lever throughout a portion only of the arc of said lever; and means for automatically enabling said member to resume its normal position and to partially return the lever to thereby move one of the switches to off position.

4. An instrumentality of the nature disclosed combining a member manually operable through a predetermined stroke; an element adapted to be displaced by said member during the latter part only of its stroke; two switches connected to be moved into on position by fall movement of said member, .and means for compelllling said element to resume its original position and to thereby return one of the switches to 01f position.

- 5. A ifirstand :a second switch; a member operable manually to throw :the second switch; :an element for throwing the first switch, :said element being arranged to be moved by said member during the latter part of the stroke of said member; and mechanism for causing said element automatically 'to resume :its original position at a retarded rate to thereby return said first switch to off position.

'6. A switch mechanism combining -a :first switch and a second switch; means operable manually to :throw both of said switches 011; and time controlled means operable automatically thereafter :to throw one' only of said switches off.

7. A switch iHlQOhZLIllSDl' combining a first and a seconds-witch; meansoperable manually to throw bothof said switches on; :a

'dev-ice operable automatically ast'ter a. predetermined time interval to -throw said first switch off; and means whereby the mentioned manually operable means :may be employed to throw the second switch off.

.8. A switch mechanism combining a first switch; :a member operable manually both to open and close the same; :a second switch; an element movable lby :sarhtl member to close said vsecond switch; and time controlled means :for opening the second switch.

#9. A motor starting switch mechanism comprising a conductor, a :fuse, a switch by mean-1s of which running current may be derived trom the conductor for passage through the fuse tot-he motor; a shunt :Erorn the conductor around the fuse by means or which. starting current may be derived from the conductor torthe motor without traversing the fuse, said shunt including a separate switch, a single operating element forsaid two-switches connected to move said two switches simultaneously into onposition, and the connections between said operating element and the shunt switch comprising a time controlled device adaptedgto automatically move the shunt switch into 01? position while the first mentioned switch stands in on position.

10. A switch mechanism combining a first and a second switch, manually operable means for operating the second switch, and means operable automatically independently of said manually operable means for operating the first switch.

In witness whereof I hereunto subscribe my'name, as attested by the two subscribing witnesses.

HUB-ERT F. KRANTZ. Witnesses:

LEON, Mrn'rz, B. CooKE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0. 

